Platen and feed roll grinder and resurfacer



Dec. 20, 1955 c. H. GROSS 2,727,337

PLATEN AND FEED ROLL GRINDER AND RESURFACER Filed Jan. 28, 1953 s Sheets-Sheet 1 IN VEN TOR.

TTORNEY Dec.- 20, 1955 c. H. GROSS PLATEN AND FEED ROLL GRINDER AND RESURFACER I5 Sheets-Sheet 2 Filed Jan. 28, 1953 INVENTOR. Z. %%T0RNEY 1955 c. H. GROSS 2,727,337

PLATEN AND FEED ROLL GRINDER AND RESURFACER Filed Jan. 28, 1953 3 Sheets-Sheet 3 INVENTOR. W 5.

United States Patent PLATEN AND FEED ROLL GRINDER AND RESURFACER Charles H. Gross, Detroit, Mich. Application January 28, 1953, Serial No. 333,733

2 Claims. (Cl. 51-103) The object of my invention is to provide a resurfacing grinder for typewriter platen and feed roll units, operative by merely inserting the roll therein.

Another object is to produce a resurfacer for cylindrical units, that will produce a ground, or polished surface on an inclosed cylindrical roll, without changing of the abrasive grinding units.

A further object is to produce a resurfacing grinder for cylindrical units that will function at different speed ratios, adjustable for producing any desired surface finish.

A still further object is to provide a platen and feed roll grinder and resurfacer that is simple in construction, easily and efiiciently operated, and that can be manufactured at a very low cost.

These several objects are attained in the preferred form by the construction and arrangement of parts as are more fully hereinafter set forth.

Similar parts on all drawings are marked by similar numerals or letters.

Fig. 1 is a side elevation of the resurfacing grinder showing the general assembly of the various operating units.

Fig. 2 is a top view of the grinding unit showing the relative position of the grinding rolls and control unit.

Fig. 3 is an end elevation of the assembled device as taken on the line 33 of Fig. 1, showing the grinding roll spacing, and special bearing adjusting means.

Fig. 4 is the opposite end elevation as taken on the line 44 of the Fig. 1, showing the special drive and control means.

Fig. 5 is an enlarged cross-sectional view taken on the line 5-5 of the Fig. 2, showing the detail construction of the control mechanism designed for variable speed ratio of the respective grinding rolls.

Fig. 6 is a vertical sectional View taken on the line 6-6 of the Fig. 1, showing the grinding dust discharging circulation system.

Fig. 7 is a similar vertical sectional view taken on the line 7-7 of the Fig. 1, showing the driving means adaptable to the variable speed ratio grinding rolls.

Fig. 8 is an enlarged end view of the grinding roll unit as taken on the line 8--8 of the Fig. 5, showing the special spring means for attaching the abrasive surface covering to the respective grinding rolls.

It is known that there are various types of surface grinding units for cylindrical rolls, but not of the variable speed ratio type and principle upon which my new device is based.

In general, my speed ratio grinder comprises dual, parallel abrasive rolls rotatably mounted within suitable aligned bearing units, the rolls being slightly separated and both rotated in the same direction. Any platen roll to be resurfaced, is placed directly thereon, resting on both grinding rolls, and retained in this position by a special contact pressure roller. The power drive is applied to both grinding roll drive pulleys one of which is designed for changing the speed ratio, controllable by connected hand adjusting means. The assembly is also provided with a special dust removing system operative by the common power unit.

I will now describe more fully the detail construction of my device, referring to the drawings and the marks thereon.

The frame A, made either of wood or metal, is preferably formed substantially rectangular in design, and is herein illustrated as constructed of rectangular vertical side panels 1 and 2, united by horizontal top panel 3 and intervening support panels 4 and 5, all securely joined together forming a rigid frame section with suitable support members for the various assembled machine units. Cross-wise the top panel 3, at opposite ends thereof, are rigidly mounted, detachable bearing blocks 6 and 7, and which carry parallel dual abrasive grinding rolls 8 and 9, rotatably mounted therein. The rolls 8 and 9 are slightly separated, and at least one roll being provided with a special excentric adjustable bearing 10, for maintaining perfect roll alignment and without surface contact therebetween. The grinding rolls are preferably made of suitable steel tubing a provided with special end bearing collars b fixedly mounted near the respective end sections, designed for receiving the respective drive shafts 11 and 12 fixedly mounted therethrough. The exterior surfaces of the respective grinding rolls are coated, or covered, with suitable abrasive material, preferably in the form of thin sheet abrasive, herein illustrated as a narrow strip 0 of emery cloth, or paper, wound continuously thereon, covering the full roll length. The abrasive sheet winding may be retained thereon by suitable adhesive material if desired, or retained by suitable mechanical lock units as illustrated by the special lock spring 13, in Fig. 8 of the drawings. On the outer end of the respective drive shafts 11 and 12 are fixedly mounted V-belt drive pulleys 14 and 15 respectively, one of which pulleys, herein illustrated as the pulley 14, being designed of compound dual side sections e and 1, see Fig. 5, the inner section e being fixedly attached directly to the supporting shaft 11, and the outer side section 7 loosely mounted thereon but securely connected to the adjoining side e by intervening dowel pins 16 slidably mounted through the wall recesses g of side e. The outer section being controlled by an adjacent engaging pressure thrust bearing 17 loosely mounted on the drive shaft, and controlled by an adjacent restraining nut 18 with lock arm x and hand adjusting screw 19 reacting against the fixed shaft collar 20 through an intervening thrust bearing 17a. Any readjustment of the hand screw 19 will allow a side displacement of the V-belt pulley section 1'- for either opening or closing same with respect to its adjoining section e. As the side section 1 is opened, the V-shaped drive belt 21 as mounted thereon, is allowed to recede within the pulley groove assuming a smaller pulley diameter, thus increasing the pulley velocity, or changing of the speed ratio between the respective pulley rotations and connected grinding rolls. vVhen sections e and f are being closed together the speed ratio may be reversed accordingly. Units 18 and 19 may be latched together, if desired, to prevent any readjustment during operation turning. The V-shaped drive belt 21 is mounted over the pulleys 14 and 15 and depressed therebetween for engaging a tightener pulley 22 as mounted on a control bar 23 pivotally attached to the frame side panel 1, the belt being extended to operatively connect with a power drive pulley 24 as mounted on a standard gear reductor unit B fixedly mounted on the frame support panel. A standard power motor C is also mounted on the frame panel 4 adjacent the reductor unit B, and is rotatably connected thereto by a shaft connector unit 25, the motor C being connected within a proper electric circuit by the ordinary means, provides controllable driving power for 3 the grinding rolls. Along opposite sides of the dual rolls 8 "and 9 are fixedly "mounted L-"shaped sheet "metal dust shields 26 securely attached to opposite ends of the respective bearing blocks 6 and 7, positioned with the L.- shaped shield edge 71 projected over the bearing block top edge to a position adjacent the respective grinding roll'surfa'ces but'without'actual contact therewith, completely inclosingthe lower roll sections "forming a closed dust chamber D thereunder. The upper L-shaped shield surface h 'is designed with a series of open dust 'holes 27 extending the frillleng'th thereof, preferably with the largerholes positioned at the outer ends of the shield and gradually diminishing in size as they near the centra'l's'hield section. "(Suitable screen material may also'be be used if'desired'). Through the central section of the frame top "panel '3 is formed an enlarged outlet channel opening 28 which carries .a curved .air flue 29 leading directly into a connected standard dust fan unit E, and which discharges the air dust into an adjoining closed filter chamb'erT positioned directly below. 'Within the filter chamber .F is mounted an outlet filter unit 30, hereinillustrated 'as a dual cylindrical casing of suitable screen material sections and k, "filled with rock wool,

orsome suitable air screening material, the fan air being forced'from chamber F 'through'the filter walls into the central open .tube k, and discharged through the open wall recess 31,rernov'ing all dust as maybe caused by the grinding process.

In'operating my device for resurfacing a typewriter platen, or feed roll Z, the roll is placed centrally over the 'dual grinding roll intersections, as illustrated in'the Figs. 1 and '2 of the drawings, and the adjustable pressure roll 32 rotated thereon for retaining .the platen roll in place 'and for producing the required operating .pressure thereon. When the V-blt ,pulleys are adjusted .to the same relative belt diameters, and the drive motor C started, the resulting speed of both rolls 8 and 9 remain exactlythe same, and both the, grinding rolls 8 and 9 and the incl'osed platen roll Z rotate together without any grinding eifect whatever. But by the proper adjustment of the hand wheel 19, opening the'pulley section '1, allowing the V-belt '21 to recede therein to a smaller pulley diameten thus increasing the speed rotation ofthe roll 8 .and "beyond the speed of the adjoining roll 9, the cutting, or grinding of the platen roll Z becomes eifective, and may be so increased as the speed ratio is increased, until the full maximum abrasive cutting is reached. 'However, the lower the speed ratio between the respective grinding rolls 8 and 9, the finer the finish, and 'which may be reduced to substantially mere surface polishing.

In replacing .the abrasive grinding roll sheet over the roll tubular surface, the projected arms m of the clamp spring -13 may be pressed together, and the inclosed end of the sheet winding c may be "removed from thereunder, and withdrawn from the tube wall slot n, allowing a fresh abrasive strip 'wound thereon, and relocked 'by'the spring 13.

Having'fully-described my platen and feed roll grinder and resurfacer, what to secure by Letters Patent is:

1. A cylindrical roll grinding machine adapted for tru- I claim as my invention and desire ing and resurfacing platen and feed roll units, and used "therewith, comprising "a rectangular support -frame" 'designed with a flat horizontal top, dual abrasive grinding rolls rotatably mounted across said horizontal frame top, said grinding rolls being positioned parallel to each other and with a slight separation therebetween, a solid drive pulley fixedly mounted on one grinding roll end, an adjustable diameter drive pulley operatively mounted on the adjoining grinding *roll .end positioned "adjacent to and in alignment with'said solid'drive pulley, operative mechanism mounted on the grinder roll end adjacent to said adjustable diameter drive pulley for varying the pulley diameter atwill .of an operator, a power a'driving unit operatively .mounted on said .support frame, also provided with a suitable drive pulley positioned in alignment with said grinding roll pulleys, a drive belt operatively mounted over said grinding roll and drive pulleys arranged for rotating said rolls in the same direction, and an adjustable pressure roll mounted on said support frame, designed and positioned to engage and retain any platen roll work in grinding position on said rolls during the resurfacing operation.

2. A platen roll grinding machine adapted for resurfacing typewriter platen and feed roll units, and used therewith, comprising a rigid support frame formed with horizontal fiat top section, shaft bearing blocks mounted across opposite ends of said frame top section, dual abrasive grinding rolls with supporting shaft members, rotatably mounted within said end bearing blocks, said rolls being positioned parallel 'to each other and with a slight space therebetween, a solid V-belt drive pulleyifixedly mounted on one grinding roll shaft end, a variable split V-belt drive pulley designed for variable pulley diameter,

operatively mounted on the adjoining grinding roll shaft end positioned adjacent to and in alignment with said solid drive pulley, operative mechanism mounted on said grinding roll shaft end adjacent to the adjustable diameter drive pulley'for adjusting said split pulley sections for varying the pulley diameter, an electric power meter mounted on the support frame also provided with a 'V- belt drive pulley pcsitionedin alignment with'the grinding roll pulleys, a'V-shaped drive belt operatively mounted over said grinding roll and motor drivepulleys, positioned and arranged for driving both of said rolls in the same direction, an adjustable pressure 'roll mounted on the support frame, positioned centrally over the grinding rolls for engaging and retaining the platen roll work thereon during grinding operations, and an air fan 'filter system connectedwith the said grinding roll section for removing the grinding dust therefrom.

References Cited in the file of this patent UNITED STATES PATENTS 1,112,345 Philipson Sept. 29, L914 1,365,448 Birchall Jan. 11, 1921 1,579,934 Heirn V Apr. 6, .1926

1,622,527 Maas Mar. 29, 1927 2,291,550 Heinichen July 28, 1942 FOREIGN PATENTS 152,632 Great Britain Sept. 19, 921 

